Nothing to Lose but Your Wires

April 6, 2003
Power cables may be the final frontier for wireless technology

Wires, cables, and connectors are some of the more mundane, albeit necessary, components in a typical machine control system, but the changes in this market are substantial and anything but mundane. Wireless communications, fiberoptics, and superconductors are the big changes we can foresee coming.

 

Wireless technology already has replaced tens of thousands of miles of wires and cables in the telecomm industry, and many observers think the same thing will occur in industrial applications. Wireless signals between the control system and remote-mounted devices "will allow remote devices to be installed quickly and moved as needed," says Arnold Offner, product manager with Phoenix Contact (

Other observers second this notion. "All data communication cables will become obsolete and will be replaced by wireless infrastructure," predicts John Gavilanes, technical/engineering manager for the Lapp Group (

As signal wires are replaced by wireless, one of the main concerns will be protecting these wireless data communications from intrusion. This promises to be a huge growth market ripe for the taking by wire, cable, and connector vendors. "Wireless will require an immense increase in communication modules with the required security to avoid bugging or virus activity," says Offner.

If wireless doesn't all but eliminate conventional copper signal cable, then fiberoptics surely will. Advances in microelectronics seem to reduce fiber costs daily, and the immunity of fiber to electrical noise provides a strong incentive for machine builders to switch to it. Easier methods of termination are also coming, and this will further promote fiber in industrial applications.

So, signal cables can be replaced by wireless or fiberoptics, but how about power cables? This is the final frontier for wireless technology. Even casual readers of science fiction know that power will be produced and transmitted in the future by a huge array of solar collectors orbiting the Earth. These arrays will beam power to earthbound collectors via laser beams.

The logical extension of this somewhat illogical premise is an entire Earth network of laser beams transmitting power from one location to the next. We would still have transmission towers, but these towers would be connected by power lasers instead of by power conductors.

 

Closer to home--and to reality--there are a number of present-day trends that can logically be extended to the future. Superconductors will become practical and their use will be widespread. The Economist magazine (www.economist.com) reports the world's first practical superconducting power cables are being installed. Detroit Edison will replace nine copper cables with three superconducting cables over a 400 m run.

The advance that led to this application was a reduction in the required operating temperature of superconducting cables from 23º K to 77º K. This means cooling can be accomplished with inexpensive, abundant, and safe liquid nitrogen. Manufacturers have increased the manufacturable length of superconductor cables many times over during the past few years, and have reduced the price considerably.

Superconducting cable once cost around $1,500 per kiloamp per meter (kA-m), the standard industry measure of conducting capacity. American Superconductor now sells wire for $200/kA-m, and expects to reduce the cost to about $50/kA-m. Reaching $25 per kA-m, the current cost of copper cable, will take a little longer.

The main reason for installing superconducting power lines is not to reduce transmission losses. These losses amount to only about 7% and those savings are offset by the energy required to cool the cables. The real advantage is that the lack of resistance means that a given thickness of superconducting cable can carry between two and 10 times as much power as the same thickness of copper. This could provide a relatively cheap way to meet rising demand for power in many applications.

Globalization looks to have a positive effect on wire and cable users, moving industry towards one regulatory agency for construction and test requirements. This should intensify competition and reduce prices.

Other inescapable and related trends in environmentalism and personal safety will also affect wire and cable producers and consumers. "All thermoplastic materials used for industrial, machinery, and building wire will be halogen-free, low-smoke, and flame-retardant," suggests Gavilanes. "All wire and cable products that use copper will have to be replaced with oxygen free metals, superconductors, or fiber."

E-mail Dan at [email protected].

www.phoenixcon.com).www.lappusa.com), a company formed in April 2002 from Olflex and Contact Electronics. "For example, cable TV will be supplanted by a satellite signal to a dish and by wireless communications from the dish to the TV."